What is the combination of quick lime and caustic soda called?

Washing soda  caustic soda  soda lime  quicklime

soda lime

The correct answer is option 3. soda lime. Soda lime is a substance made up of caustic soda, which is just sodium hydroxide, and quicklime, which is calcium oxide. They are denoted chemically by the formulas NaOH and CaO, respectively.